Biochemical Properties Research Articles

Effect of Organic Manure and Bio-fertilizers on the Quality Enhancement of Dragon Fruit (Hylocereus costaricensis) (Web.) Britton and Rose

Aims: This study aimed to assess the effects of vermicompost and bio-fertilizers on the quality attributes of Red Skin, Purple Flesh dragon fruit (Hylocereus costaricensis L.), focusing on improving fruit size, biochemical composition, and overall fruit quality through sustainable agricultural practices. Study Design: The experiment was conducted using a randomized block design, consisting of eleven treatments with three replications, including a control. The treatments varied in the combination of vermicompost and bio-fertilizers (Azotobacter, VAM, and PSB) applied to dragon fruit plants. Place and Duration of Study: The study was carried out from 2022 to 2024 at the Orchard, Department of Fruit Science, C.S.A. University of Agriculture and Technology, Kanpur, India. Methodology: Eleven treatments were testedT1-Control, T2-Vermicompost @ 0.5 kg/plant, T3-Azotobacter @ 50 g/plant, T4-VAM @ 100 g/plant, T5-PSB @ 50 g/plant, T6-Vermicompost @ 0.5 kg/plant + Azotobacter @ 50 g/plant, T7-Vermicompost @ 0.5 kg/plant + VAM @ 100 g/plant, T8-Vermicompost @ 0.5 kg/plant + PSB @ 50 g/plant, T9-Vermicompost @ 0.5 kg/plant + Azotobacter @ 50 g/plant + VAM @ 100 g/plant, T10-Vermicompost @ 0.5 kg/plant + Azotobacter @ 50 g/plant + PSB @ 50 g/plant and T11-Vermicompost @ 0.5 kg/plant + VAM @ 100 g/plant + PSB @ 50 g/plant. Each treatment was replicated three times.A basal dose of FYM (5 kg/plant), Trichoderma (25 g/plant), and neem cake (50 g/plant) was applied uniformly. Various quality parameters, such as fruit weight, size, pulp-to-peel ratio, and biochemical properties (total soluble solids, total sugars, ascorbic acid, and acidity), were measured to evaluate fruit quality. Results: The application of T₁₁ (Vermicompost @ 0.5 kg/plant + VAM @ 100 g/plant + PSB @ 50 g/plant) resulted in the highest fruit weight (280.50 g), length (9.42 cm), diameter (7.64 cm), and volume (254.98 cm³). T₁₁ also exhibited superior biochemical attributes, including the highest total soluble solids (15.76° Brix), total sugars (9.42%), and ascorbic acid content (14.26 mg/100 g), with the lowest acidity (0.17%) and highest TSS/acid ratio (92.85). Conclusion: The integration of vermicompost with VAM and PSB significantly enhanced dragon fruit quality by improving nutrient availability, optimizing physiological processes, and enhancing fruit size and biochemical attributes. These findings suggest that combining organic amendments and beneficial microbes offers a sustainable approach to improving dragon fruit production in tropical regions.

Biochemical Characterization of a GH11 Xylanase from Xylanase-Producing Trichoderma citrinoviride.

Xylan, a prevalent component of lignocellulose, ranks as the second most abundant carbohydrate in nature. Endo-1,4-xylanase, pivotal for its ability to cleave β-1,4-glycosidic linkages within xylan, is crucial for various applications in the food/feed processing, biofuel production, and paper/pulp industries. Although Trichoderma citrinoviride is renowned for its robust xylan-degrading capacity, the biochemical properties of xylanases derived from T. citrinoviride remain largely uncharacterized. Therefore, this study was conducted to explore the biochemical characteristics of a glycoside hydrolase family 11 xylanase derived from T. citrinoviride (TciGH11). This newly identified enzyme efficiently hydrolyzed beechwood xylan into xylooligosaccharides, exhibiting optimal activity at pH 4.5 and 50°C, with a specific activity of 1801.5 U mg-1 against beechwood xylan. Kinetic analysis revealed a Michaelis constant (Km), turnover number (kcat), and catalytic efficiency (kcat/Km) of 3.82mgml-1, 977.8s-1, and 256.0mlmg-1s-1, respectively. Structural modeling analysis demonstrated that the non-conserved residues in TciGH11, specifically Glu162 and Ser165, affected the substrate binding properties, potentially resulting in different enzymatic activity compared to that of other xylanases from the Tricoderma genus. Overall, these results could be instrumental in advancing the utilization of lignocellulosic biomass, thereby supporting sustainable bioprocessing of lignocellulosic biomass.

Change of Total Phenolic Substance, Total Flavonoid Substance, Ergothioneine Concentration, Antioxidant and Antibacterial Properties in Edible Mushrooms Under The Influence of UV-B Radiation

Aim of study: This study investigated the effects of UV-B radiation on antioxidant, phenolic and flavonoid, ergothioneine, amino acids, and antimicrobial properties in four edible mushroom species. Area of study: The mushrooms were verified according to their microscopic and macroscopic features at Kastamonu University, Faculty of Forestry. Material and method: DPPH measurements, total phenolic, total flavonoid, ergothioneine, and amino acid analyses, antibacterial measurements were also performed for mushroom extracts. Main results: Results showed that low UV-B enhanced antioxidant and antibacterial activities, with L. edodes and P. ostreatus exhibiting the highest antioxidant levels. P. eryngii showed a steady increase in phenolic and flavonoid contents. Ergothioneine and glutamic acid concentrations peaked under low UV-B. Research highlights: The findings indicate that UV-B exposure significantly influences the biochemical properties of mushrooms.

Identification of lactic acid bacteria isolated from traditional cheeses of the Black Sea Region

The aim of this study was to isolate and to identify lactic acid bacteria from traditional cheeses of the Black See Region. Artvin Şor, Giresun Tecen, Kargı Tulum, Ordu Kesik and Trabzon Telli cheese were used as cheese samples of the Black Sea Region. The number of lactic acid bacteria in traditional cheese of the Black Sea Region were ranged from 4.62 ± 0.76 and to 7.87 ± 0.64 log cfu·g-1. Gram–positive and catalase–negative colonies were evaluated as lactic acid bacteria based on the morphological and biochemical properties. According to biochemical analysis results, 39 lactic acid bacteria strains were identified by 16S rDNA isolated from cheese samples. Based on the sequence analysis, the indigenous lactic acid bacteria population was identified as Enterococcus faecium (35.9%), as Levilactobacillus brevis (12.8%), as Lactiplantibacillus plantarum (15.3%), as Pediococcus acidilactici (7.6%), as Enterococcus durans (7.6%), as Lacticaseibacillus paracasei (5.1%), as Lacticaseibacillus casei (7.6%), as Leuconostoc mesenteroides (2.5%), as Leuconostoc lactis (2.5%) and as Weissella cibaria (2.5%). Enterococcus spp. was the dominant lactic acid bacteria in cheese sample. The present findings revealed that lactic acid bacteria populations varied depending on cheese types in terms of cell counts and diversity.

ADAT3 variants disrupt the activity of the ADAT tRNA deaminase complex and impair neuronal migration.

The ADAT2/ADAT3 (ADAT) complex catalyzes the adenosine to inosine modification at the wobble position of eukaryotic tRNAs. Mutations in ADAT3, the catalytically inactive subunit of the ADAT2/ADAT3 complex, have been identified in patients presenting with severe neurodevelopmental disorders. Yet, the physiological function of ADAT2/ADAT3 complex during brain development remains totally unknown. Here, we investigated the role of the ADAT2/ADAT3 complex in cortical development. First, we reported 21 neurodevelopmental disorders patients carrying biallelic variants in ADAT3. Second, we used structural, biochemical, and enzymatic assays to deeply characterize the impact of those variants on ADAT2/ADAT3 structure, biochemical properties, enzymatic activity and tRNAs editing and abundance. Finally, in vivo complementation assays were performed to correlate functional deficits with neuronal migration defects in the developing mouse cortex. Our results showed that maintaining a proper level of ADAT2/ADAT3 catalytic activity is essential for radial migration of projection neurons in the developing mouse cortex. We demonstrated that the identified ADAT3 variants significantly impaired the abundance and, for some, the activity of the complex, leading to a substantial decrease in I34 levels with direct consequence on their steady-state. We correlated the severity of the migration phenotype with the degree of the loss of function caused by the variants. Altogether, our results highlight the critical role of ADAT2/ADAT3 during cortical development and provide cellular and molecular insights into the pathogenic mechanisms underlying ADAT3-related neurodevelopmental disorders.

Quantification of Biochemical and Antioxidant Properties of Contrasting Common Purslane Populations

Quantification of Biochemical and Antioxidant Properties of Contrasting Common Purslane Populations

Impact of integrated nutrient management on growth, productivity and soil biochemical property of kharif rice

An experiment was conducted during kharif season of 2022 and 2023 to evaluate the performance of rice under integrated nutrient management using inorganic, organic and nano fertilizers. The experiment was designed as a Randomized Block Design (RBD) for rice during Kharif. The rice variety “Kalinga Dhan 1204” was sown in July with seven treatments: T1- Control (No fertilizer), T2- Full soil test based nitrogen recommendation (STBNR) through inorganic sources, T3- Full STBNR through organic sources (FYM), T4- Full STBNR through 50 % organic (FYM) + 50 % inorganic sources, T5- Full STBNR through 25 % organic (FYM) + 75 % inorganic sources, T6- 50 % N through inorganic sources + 2 nano urea spray (Tillering & PI stage), T7- 75% N through inorganic sources + 2 nano urea spray (Tillering & PI stage). Pooled data indicated application of Full STBNR through 25 % organic (FYM) + 75 % inorganic sources resulted in highest plant height (117.05 cm), leaf area index (LAI) (5.26), dry matter production per square meter (1085.50 g m-2), number of tillers per square meter (393.17), panicle length (26.60 cm), panicle weight (2.96 g), number of filled grains per panicle (166.67), grain yield (6.64 t ha-1), straw yield (7.45 t ha-1) and harvest index (47.13 %).

Biochemical characterization of a bilfunctional endoglucanase/glucomannanase derived from mountain soil.

Metagenomics is increasingly recognized as a vital technique for exploring uncultured microorganisms, with one key application being the discovery of novel enzymes for industrial use. This study identified an endoglucanase gene from soil metagenome, termed ZFEG1801, which was expressed in E. coli BL21, purified, and characterized for its biochemical properties. The 72.8 kDa recombinant protein exhibited hydrolytic activity against sodium carboxymethyl cellulose (CMC) and konjac glucomannan (KG), with activities of 12.1 U/mg and 42.1 U/mg, respectively. The enzyme displayed optimal activity at pH 5 for CMC and pH 6 for KG, with broad pH stability ranging from 5 to 9. The optimal temperature was 40°C, and it remained thermally stable between 20 and 40°C, retaining over 60% of its activity. The enzyme activity remained stable in the presence of most metal ions; however, CMCase activity was inhibited by Cu2+, while glucomannanase activity was inhibited by Mn2+, Fe3+, and Ca2+. The catalytic efficiency towards both substrates was reduced by addition of SDS, DMSO, ethanol, isopropanol and acetonitrile. The Vmax and Km of the purified recombinant enzyme were 106.4 μmol/L/min and 4.9 mg/mL for CMC, and 833.3 μmol/L/min and 11.1 mg/mL for KG, respectively. The dual catalytic properties of ZFEG1801, broad pH stability and resistance to additives, demonstrate its potential for use in various biomass degradation processes.

Targeting the retinoid signaling pathway with YCT-529 for effective and reversible oral contraception in mice and primates

BackgroundThe retinoic acid receptor alpha (Rarα) has been validated as a male contraceptive target by genetic knockouts resulting in male sterility. The effects on spermatogenesis in the absence of RARα resemble the loss of RAR signaling in vitamin A deficiency, and the mice are otherwise normal. The effects on spermatogenesis in animals treated orally with the dual RARα/RARγ antagonist BMS-189453 closely phenocopies the absence of RARα function. Notably, the resulting male sterility is reversible. We, therefore, wished to identify RARα−selective inhibitors for potential male non-hormonal contraception.MethodsYCT-529 was investigated for RARα selective inhibition, physicochemical characteristics, oral bioavailability, and pharmacokinetic properties in mice and non-human primates. It was assessed in mouse mating trials to determine the most effective dosing regimen to induce infertility in male mice and in male non-human primates to reduce sperm levels.ResultsCharacterization of YCT-529 shows suitable biochemical, physicochemical, and pharmacokinetic properties for in vivo testing. YCT-529 inhibits mouse fertility of male mice within 4 weeks of oral administration, correlating with disrupted spermatogenesis demonstrating specific inhibition of the RARα pathway. Within 6 weeks after cessation of dosing, mouse fertility reverses. Furthermore, YCT-529 inhibits sperm production in a non-human primate model within 2 weeks of oral dosing without adverse side effects. Within 10–15 weeks after cessation of dosing, non-human primates’ sperm counts fully reverses.ConclusionsThese results lay the groundwork for evaluating YCT-529 in human clinical trials.

Evaluation of Phytochemical Constituents, Antioxidant & Anti-Diabetic Activity of Seaweed Turbinaria Decurrens Collected from Gulf of Mannar, Tamil Nadu, India

The genus Turbinaria stands out as a prominent and widely distributed member of the brown algae. This species is characterized by distinct morphology, ecological importance, and biochemical properties. In the present study, taxonomical, molecular identification along with antioxidant and anti-diabetic activity of the different extracts (acetone, aqueous & methanol) of T.decurrrens was determined. The preliminary phytochemical components were investigated qualitatively and quantitatively by using standard methods and confirmed the presence of variety of phytoactive components such as coumarins, glycosides, phenols tannins, terpenoids and saponins. The collected seaweed sample was identified by molecular approaches using QIAGEN DNA isolation kit and the BLAST program at the NCBI website that showed se quences similarities with existing seaweed rbcL gene sequences up to 99.21%. "The antioxidant activity of three crude extracts was evaluated by various antioxidant assays viz DPPH and ABTS." The findings revealed potent scavenging activity of ABTS, with a minimum inhibitory concentration (IC50) of 1.06mg/ml for the methanolic extract while the DPPH assay indicated an IC50 value 1.56mg/ml. The investigation into the antidiabetic properties of seaweed extract revealed that the methanolic extract of T.decurrens exhibited the most significant inhibitory activity against α-amylase and α-glucosidase enzymes with IC50 value of 1.8 mg/ml and 1.40mg/ml respectively. The presence of phytochemical metabolites contributes to both antioxidant activity and anti-diabetic activities. These results indicate that the extract of T.decurrens serve as a natural source of antioxidants and anti-diabetics compounds possessing the potential to address a wide array of serious health conditions.

Insights into therapeutic potential and practical applications of natural toxins from poisonous mushrooms.

IntroductionMushrooms, belonging to the phyla Ascomycota and Basidiomycota, comprise approximately 14,000 known species, among which a small fraction are toxic. While toxic mushrooms are primarily associated with adverse health effects, recent research highlights their potential as sources of bioactive compounds with promising therapeutic applications.MethodsA systematic review was conducted using four major electronic databases: Web of Science, Google Scholar, PubMed, and ScienceDirect. The literature search, completed on July 1, 2024, utilized keywords including "Poisonous mushrooms," "Mushroom toxins," "Mycotoxins," "Beta-glucans," "Psilocybin," and "Therapeutic applications." Articles were selected based on specific inclusion criteria, focusing on studies investigating the biochemical, toxicological, and pharmacological properties of toxic mushroom compounds. Studies unrelated to mushrooms, non-peer-reviewed sources, or those with outdated or incomplete data were excluded.ResultsThis review examines key toxic mushroom compounds such as amanitins, phallotoxins, ibotenic acid, muscimol, orellanine, and gyromitrin, emphasizing their biosynthesis, structural features, and health effects. Despite their toxicity, compounds like beta-glucans, polysaccharides, lectins, and psilocybin exhibit immune-modulating, anticancer, and neuroprotective properties. These bioactive compounds have shown promise in targeting cancer stem cells and enhancing neurotransmitter activity, positioning them as potential therapeutic agents.DiscussionUnderstanding the therapeutic potential of toxic mushroom-derived bioactive compounds bridges toxicology and pharmacology, offering novel avenues for drug discovery. Comparative analysis with existing treatments highlights their unique advantages in modern medicine.

Hydrolysis-deficient mosaic microtubules as faithful mimics of the GTP cap

A critical feature of microtubules is their GTP cap, a stabilizing GTP-tubulin rich region at growing microtubule ends. Microtubules polymerized in the presence of GTP analogs or from GTP hydrolysis-deficient tubulin mutants have been used as GTP-cap mimics for structural and biochemical studies. However, these analogs and mutants generate microtubules with diverse biochemical properties and lattice structures, leaving it unclear what is the most faithful GTP mimic and hence the structure of the GTP cap. Here, we generate a hydrolysis-deficient human tubulin mutant, αE254Q, with the smallest possible modification. We show that αE254Q-microtubules are stable, but still exhibit mild mutation-induced growth abnormalities. However, mixing two GTP hydrolysis-deficient tubulin mutants, αE254Q and αE254N, at an optimized ratio eliminates growth and lattice abnormalities, indicating that these ‘mosaic microtubules’ are faithful GTP cap mimics. Their cryo-electron microscopy structure reveals that longitudinal lattice expansion, but not protofilament twist, is the primary structural feature distinguishing the GTP-tubulin containing cap from the GDP-tubulin containing microtubule shaft. However, alterations in protofilament twist may be transiently needed to allow lattice compaction and GTP hydrolysis. Together, our results provide insights into the structural origin of GTP cap stability, the pathway of GTP hydrolysis and hence microtubule dynamic instability.

A Study on the Effect of Dielectric Barrier Discharge on the Germination and Surface Characteristics of Tomato Seeds

ABSTRACTPlasma seed treatment has become a well‐established technique for seed pretreatment. This study investigates the influence of treatment time, applied voltage and other parameters upon seed germination rate, as well as the effect of plasma treatment on water absorption of seeds. To elucidate the mechanisms underlying plasma action on seeds, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and X‐ray Photoelectron Spectroscopy (XPS) were employed to characterize the physical and biochemical properties of the seeds before and after treatment. The results reveal that plasma treatment can significantly increase the seed germination rate. Furthermore, the results of this study provide a valuable understanding of the interactions of plasma with the surface of tomato seeds, suggesting promising applications for large‐scale agricultural practices.

Biochemical properties of molybdenum cofactor isolated from fish liver.

Recent studies have demonstrated that the fish liver protein fraction extract obtained by gel filtration exhibits nitric oxide synthase (NOS)-independent NO synthase from nitrates and nitrites. This activity was attributed to the molybdenum enzymes (Mo-enzymes) group which was already demonstrated in mammals. However, the evidence that NOS-independent NO synthase activity can be classified as a fish Mo-enzyme has been poorly demonstrated. In mammals, Mo-enzymes NOS-independent NO synthase activity occurs at the molybdenum center. We studied the ability of molybdenum cofactor (Mo-co) isolated from the protein fraction of fish liver extract to restore the NADPH-nitrate reductase (NADPH-NR) activity from Neurospora crassa nit-1. Our results demonstrated that Mo-co from the extract from fish liver was able to recover NADPH-NR activity in theextract of N. crassa nit-1, thereby possessing the ability to reduce nitrogen compounds. However, the oxidation of Mo-co from fish liver destabilizes molybdenum, leading to its inactivation. However, the results obtained under anaerobic conditions with dithionite indicate that Mo remains bound to Mo-co under highly reducing conditions. This may also indicate that the availability of Mo is not the sole factor affecting the activity of Mo-enzymes, also oxygen content after the synthesis of mature Mo-co may play a role in cofactor inactivation.

State-dependent motion of a genetically encoded fluorescent biosensor

Genetically encoded biosensors can measure biochemical properties such as small-molecule concentrations with single-cell resolution, even in vivo. Despite their utility, these sensors are "black boxes": Very little is known about the structures of their low- and high-fluorescence states or what features are required to transition between them. We used LiLac, a lactate biosensor with a quantitative fluorescence-lifetime readout, as a model system to address these questions. X-ray crystal structures and engineered high-affinity metal bridges demonstrate that LiLac exhibits a large interdomain twist motion that pulls the fluorescent protein away from a "sealed," high-lifetime state in the absence of lactate to a "cracked," low-lifetime state in its presence. Understanding the structures and dynamics of LiLac will help to think about and engineer other fluorescent biosensors.

The Combined Effect of Lighting and Zinc on the Nutritional Quality of Lettuce (Lactuca sativa L.) Grown in Hydroponics

The nutritional quality and biochemical properties of ‘Little Gem’ (Lactuca sativa L.) lettuce grown hydroponically can be enhanced by Zn and white light. This study investigated the combined effects of wide-spectrum white LED lighting parameters and Zn doses on the Zn accumulation, enzymatic and non-enzymatic antioxidants, sugars, and protein content of lettuce. Broad-spectrum 3500 K light combined with a 5 ppm Zn solution led to a 7% increase in Zn accumulation in lettuce, compared to 3000 K and 4000 K lighting conditions. The 5 ppm Zn dose combined with 3000 K and 4000 K lighting affected DPPH and ABTS scavenging activity and Fe-reducing antioxidant power. Additionally, this combination influenced chlorophyll b, maltose, superoxide dismutase, and ascorbate peroxidase levels. Furthermore, the 1 and 5 ppm Zn doses at 4000 K impacted carotenoids such as neoxanthin, lutein, zeaxanthin, and total protein content. In lettuce exposed to a 1 ppm Zn dose combined with 3000 K and 3500 K lighting, impact was found on total phenolic compounds, sucrose, chlorophyll a, raffinose, fructose, glucose, carotene, violaxanthin, and xanthophylls. The study suggests that lighting and Zn concentrations significantly impact lettuce growth, biochemical properties, and nutritional quality, particularly at the baby leaf stage.

Determining the optimal harvest time for pomegranate variety wonderful in semi-arid climate

Due to limited local knowledge regarding the optimal harvest time for this non-native variety, a two-year study (2021–2022) was conducted using a randomized complete block design with four blocks. This study aimed to determine the ideal harvest time based on quantitative and qualitative fruit characteristics in saveh, which has a semi-arid climate. Twelve similarly sized trees were selected for each orchard, and fruits were harvested at three-time intervals: 155 days after flowering (DAF) (September 27), 170 DAF (October 12), and 185 DAF (October 27). Ten fruits from four sides of the tree canopy were collected and analyzed for physical and biochemical properties. The results showed that harvest time significantly affected fruit weight, aril weight, and juice percentage positively, while it negatively impacted rind percentage. The first harvest date yielded the lowest quantitative and qualitative traits, with incomplete skin and aril coloration. By the third harvest, pomegranate fruits exhibited the highest total soluble solids (17.76 °Brix), pH (3.41), and anthocyanin content (32.56 mg/L), along with the lowest total phenols (17.28 mg GAE/L), antioxidant capacity (79.78%), and titratable acidity (1.11%), resulting in the highest flavor or ripening index (16.31). In addition, cracking rates increased substantially, reaching 30.25% by the third harvest, compared to negligible levels of 20.72% by the second harvest. Juice percentage and aril weight improved significantly with delayed harvest, peaking on October 27. These findings suggest that October 12–27 is the optimal harvest window for superior fruit quality while considering the risk of fruit cracking. This study provides practical insights into harvest timing for maximizing the marketability and nutritional value of ‘Wonderful’ pomegranates in semi-arid climates.

Unraveling Structural and Biochemical Insights into a Novel Thermo-Alkaline Pectate Lyase from Caldicellulosiruptor bescii for Sustainable Fabric Bioscouring.

Pectate lyase (PL) holds significant potential for applications in various industries. However, the existing PL was unable to adapt to thermo-alkaline industrial environments. In this work, a PL from Caldicellulosiruptor bescii DSM 6725 (hereafter, CbPelD) was studied to disclose its structural and biochemical properties. CbPelD consisted of a putative signal peptide sequence, a short linker region, and a catalytic domain (PelD-II), along with an exoacting β-fructofuranosidase domain (PelD-I). In molecular dynamics simulation, PelD-II demonstrated significantly higher activity and thermal stability compared to other truncated enzymes of CbPelD. The optimal pH and temperature for PelD-II were 10.0 and 60 °C, respectively, with the specific activity increasing by 164-223% in the presence of Ca2+ or Ni2+. The exotype PelD-II exhibited efficient degradation of polygalacturonic acid (PGA) into unsaturated galacturonic acid (uG1), digalacturonic acid (uG2), and trigalacturonic acid (uG3). In the bioscouring assay, PelD-II exhibited a significant increase in the wetted fabric area to 6.072 ± 0.684 cm2, which was about 7.9 times higher than untreated fabric. Scanning electron microscopy further revealed that treatment with PelD-II resulted in a smoother fiber surface, providing direct visual confirmation of the enzyme's action. These results highlight the potential of PelD-II for applications in the textile industries.

Overview of North American Isolates of Chronic Wasting Disease Used for Strain Research

Chronic Wasting Disease (CWD) is a prion disease that affects Cervidae species, and is the only known prion disease transmitted among wildlife species. The key pathological feature is the conversion of the normal prion protein (PrPC) misfolding into abnormal forms (PrPSc), triggering the onset of CWD infections. The misfolding can generate distinct PrPSc conformations (strains) giving rise to diverse disease phenotypes encompassing pathology, incubation period, and clinical signs. These phenotypes operationally define distinct prion strains, a pivotal element in monitoring CWD spread and zoonotic potential—a complex endeavor compounded by defining and tracking CWD strains. This review pursues a tripartite objective: 1. to address the intricate challenges inherent in ongoing CWD strain classification; 2. to provide an overview of the known CWD-infected isolates, the strains they represent and their passage history; and 3. to describe the spatial diversity of CWD strains in North America, enriching our understanding of CWD strain dynamics. By delving into these dimensions, this review sheds light on the intricate interplay among polymorphisms, biochemical properties, and clinical expressions of CWD. This endeavor aims to elevate the trajectory of CWD research, advancing our insight into prion disease.

Crystal Structure of Papain-Like Cysteine Protease, Calotropain FI, Purified from the Latex of Calotropis gigantea.

The latex of Calotropis gigantea and Calotropis procera elute as two distinct peaks on cation exchange chromatography. One of the peaks is reported to possess multiple papain-like cysteine proteases with different biochemical properties that have been identified with different names. This is mainly due to the absence of a primary sequence for the proteases. Here, we report the crystal structures of calotropain FI from C. gigantea bound to the inhibitor E64 at pH 6 and 9 at 1.25 and 1.4 Å, respectively. Both structures are identical and are very similar to ervatamin B and papain structures. The high quality of electron density maps revealed the primary sequence of calotropain FI. The sequence comparison shows that calotropain FI from C. gigantea is orthologous to procerain, CpCp1-3, and SnuCalCp03 from C. procera and rather distinct from procerain B.